套作蚕豆对梨园土壤肥力和微生物群落结构的影响OA北大核心CSTPCD

To investigate the effects of intercropping faba beans on soil fertility and microbial communities in pear orchards,soil samples were collected from no intercropping(CK),intercropped Sucan 3 Hao(CT1),intercropped Sucan 4 Hao(CT2),and intercropped Cican 1 Hao(CT3,local variety)treatments during the seedling stage,flowering stage,and maturity stage.The samples were analyzed for soil physicochemical properties,microbial activity,and community structures.The results showed that after intercropping with faba beans,the nitrate nitrogen(NO-3-N),and available phosphorus(Olsen P)increased during the seedling stage.During the flowering stage,soil electrical conductivity,dissolved organic carbon(DOC),dissolved organic nitrogen(DON),and NO-3-N contents significantly increased,while pH and Olsen P contents significantly decreased.Intercropping with faba beans increased soil microbial biomass carbon(MBC),especially CT1 and CT2 increased by 36%and 51%,respectively at the maturity stage compared with CK(P＜0.05),and decreased the activity of hydrolytic enzymes related to the degradation of carbon,nitrogen,and phosphorus.Additionally,intercropping with faba beans increased the bacterial richness index and the Shannon index.It also increased the relative abundances of bacteria from the Planctomycetota,Firmicutes,Gemmatimonadetes,and Verrucomicrobia phyla,while decreasing the relative abundances of bacteria from the Proteobacteria,Actinobacteria,and Acidobacteria phyla.Mantel and CCA analyses indicated that pH and NO-3-N were important driving factors for microbial activity,and MBC significantly affected the bacterial community structures.Our results indicates that long-term intercropping of faba beans helps to increase soil microbial biomass and diversity,playing a crucial role in maintaining soil micro-ecological diversity.